Use Google reCaptcha – Prevent Spam, Digitize the World

Google reCaptcha is an effective way to prevent bots from spamming your website. What reCaptcha does is very simple – it shows an image to be solved to complete a manual action, e.g. for successful submission of a form.

Users have to type in the text they find in the image to proceed.

This is something that a human can easily do, but bots cannot. When they don’t recognize the numbers, they will fail to submit the form – and that means, no spam for you.

The same principle is applied by many spam preventing tools, but reCaptcha goes one step further. The images that humans recognize and enter as text will add up towards the effort to digitize “stuff”. This may include –

Text in books that are deemed unreadable by computers

Street signs (e.g. in Google maps)

Annotate images that a machine cannot do (yet)

The digitized text will go into a database of images/annotated texts and help in furthering machine learning for images discovered in the future.

Overall, you are helping to save the world by giving more power to our machine overlords, and at the same time preventing spam on your website.

reCaptcha Plugins for WordPress

reCaptcha is free.

There are a number of plugins that use the free API to prevent bots from submitting automatic registrations, comments, or through any other forms. To use reCAPTCHA you would have to register your sites, and get the free key from here.

You can then use custom code in your forms to activate reCaptcha. Or, make it really simple by installing a plugin for the purpose. The best, free reCaptcha WordPress plugins are below.

WP-reCAPTCHA

WP-reCaptcha is a free plugin that uses the reCaptcha API to show captcha images in your forms.

You can choose WP-reCAPTCHA to show reCaptcha for WordPress registration forms, and comment forms. To use WP-reCAPTCHA just install it from wordpress.org, put in your API keys, and you are set.

The plugin options are simple, and good enough to get the job done.

WP-reCAPTCHA shows a clean theme that blends in with your website. In other options: you can choose the language for reCaptcha, set the tab index, and use your own error messages.

Better WordPress reCAPTCHA

Better WP reCaptcha is what I used on some of my websites. It does its job pretty well in the look & feel and customization department in addition to seamless integration with reCaptcha service.

In addition to normal registration, comment forms, this plugin also works well with Contact Form 7. You can customize BWP reCaptcha by adding custom CSS, and it sits pretty with rest of your website. You could also choose to hide the captcha for defined roles, for users who had at least one approved comment, and use custom error messages.

The best part of BWP reCaptcha is that it can work along with Akismet. This way you don’t force legitimate users from entering captcha for their actions, while intelligently decide whoever looks like spam and challenge them with captcha.